Healing

Question 1

Types of healing

Answer 1

Fibrosis

Regeneration

Question 2

Steps in Fibrosis

Answer 2

Removal of debris
Formation of granulation tissue
Scarring

Question 3

Stem cells types

Answer 3

Embryonic
Marrow stromal
Induced pluripotent

Question 4

special microenvironments of Adult stem cells

Answer 4

Niches

Question 5

Growth Factor effects

Answer 5

Cell proliferation
Differentiation
Cell migration
Angiogenesis and Fibrogenesis

Question 6

GF sources

Answer 6

Macrophages
platelets
T cells
fibroblasts
endothelial cells

Question 7

GF receptors

Answer 7

Receptors with intrinsic kinase activity
G-protein-coupled receptors
Receptors without intrinsic kinase activity

Question 8

GFs

Answer 8

Transforming GF alpha & beta (TGF-β & TGF-α)  
Epidermal GF (EGF) 
Hepatocyte GF (HGF) 
Vascular Endothelial GF (VEGF) 
Platelet Derived GF (PDGF)
Cytokines

Question 9

Main components of ECM

Answer 9

Fibers(collagens & glycoproteins)
Basement membranes & surrounding vessels, (non-fibrillar collagen & laminin)
Adhesive glycoproteins (integrins), proteoglycans & hyaluronic acid)

Question 10

Granulation tissue

Answer 10

Fibroblast and myofibroblasts
New blood vessels
Inflammation cells

Question 11

Functions of ECM

Answer 11

Mechanical support (collagen& elastin)
Substrate for cell growth & the formation of tissue micro environments
Regulates cell proliferation & differentiation

Question 12

stimulate cells via cellular integrin receptors

Answer 12

Fibronectin & laminin

Question 13

Proteoglycans

Answer 13

bind GFs & display them at high concentration

Question 14

Sources of new blood vessels

Answer 14

Angioblasts from bone marrow

Pre existing blood vessels

Question 15

Angiogenesis stimulated by

Answer 15

Vascular endothelial growth factors

Question 16

TGF beta in angiogenesis

Answer 16

Stabilizes new bvs by enhancing production of ECM proteins

Question 17

PDGF and Angiopoietins

Answer 17

Recruit smooth muscles and peri endothelial cells respectively

Question 18

Fetal cutaneous wounds heal without scar

Answer 18

TGF β isoforms (non-fibrogenic)
lack of osteopontin
absence of a TH2 response

Question 19

1° intention Minutes

Answer 19

formation of blood Clot => scab

Question 20

1° intention 24 hrs

Answer 20

neutrophils, regenerating epithelial cells forms a thin layer & covers the wound beneath the scab

Question 21

1° intention 3 days

Answer 21

granulation tissue, thick epithelial layer

Question 22

1° intention 5-7days

Answer 22

granulation tissue fills incisional space & abundant collagen bridging the incision, keratin

Question 23

1° intention 2wks

Answer 23

fibroblast proliferation & collagen deposition

Question 24

1° intention 4+ wks

Answer 24

capillaries involution, leaving a pale (white) avascular scar

Question 25

Rate of wound contraction depends on

Answer 25

The degree of tissue laxity | Shape of wound

Question 26

Bone fracture types

Answer 26

Simple | Compound

Question 27

Bone fracture healing

Answer 27

Direct | Indirect

Question 28

Direct fracture healing

Answer 28

Fracture is stable | In corticoid and cancellous bone

Question 29

Indirect fracture healing steps

Answer 29

Hematoma and mild acute inflammation Osteoclast and macrophage action Osteogenic granulation tissue External & internal callus are reabsorbed Woven bone remodeled & change to lamellar bone

Question 30

Abnormal bone healing

Answer 30

Delayed union Non-union (pseudoarthrosis) Malunion Refracturing

Question 31

Scar formation in CNS

Answer 31

By Astrocytes known as gliosis | Characterized by severe neural loss

Question 32

Abnormal tissue healing

Answer 32

1. Deficient scar formation 2. Excessive formation of the repair components 3. Contractures (excessive contraction) 4. Atrophic /hypotrophic scar (sunken) 5. Implantation cyst 6. Pigment changes: depigmented (vitiligo) /hyperpigmented

Question 33

Deficient scar formation

Answer 33

Ulcers | Wound dehiscence or rupture

Question 34

Ulceration

Answer 34

Inadequate vascularization | Diabetic peripheral neuropathy

Question 35

Rupture

Answer 35

Error in suture placement Abdominal pressure Deep wound infection

Question 36

Excessive formation of repair components causes

Answer 36

Hypertrophic scars within the limit of original wound and regresses spontaneously Keloids outside the limit of the original wound doesn’t resolve spontaneously

Question 37

Local factors affecting healing

Answer 37

``` Necrosis Foreign bodies Infections Pressure Radiation Location Edema Drying ```

Question 38

Systemic factors affecting tissue healing

Answer 38

``` Nutrition Age Steroid, immunosuppressants Body type: obesity Smoking Vascular insufficiency Smoking ```